HOLC, Redlining and Our old Census Friend

A short description of the post.

Jacob Ford true
2022-06-26

Collapsed Zone Density

HOLC Lines

Source

Combine Zoning & HOLC

pal <- colorFactor(
  palette='Dark2',
  domain=res_zones$density
)

pal_holc <- colorFactor(
  palette=c("green","blue", "yellow", "red"),
  domain=durham_lines$holc_grade
)

combined_map <- leaflet() %>%
  addProviderTiles("CartoDB.Positron") %>%
  setView(-78.90390102117877,35.998220055791876,  zoom=14)%>%
  addPolygons(data=res_zones,
              group="Zoning",
              weight=1,
              color=~pal(density),
              popup=paste("Zone Type: ", res_zones$zone_flag, "<br>",
                          "Detailed Zone:", res_zones$density, "<br>",
                          "Zoned for ", res_zones$dwell_units, "Dwell Units maximum", "<br>",
                          "Acres: ", res_zones$ACRES)) %>%
    addPolygons(data=durham_lines,
              group="HOLC",
              weight=1,
              color=~pal_holc(holc_grade),
              popup=paste("HOLC Grade: ", durham_lines$holc_grade, "<br>")) %>%
  addLegend(
    position="bottomright",
    group="Zoning",
    pal=pal,
    values=res_zones$density
  ) %>%
  
    addLegend(
    position="bottomright",
    group="HOLC",
    pal=pal_holc,
    values=durham_lines$holc_grade
  ) %>%


  addLayersControl(overlayGroups = c("Zoning", "HOLC"))

combined_map %>% hideGroup("Zoning") 

Further analysis questions:

  1. using centroid tagging, what is the proportion of Durham zones that are represented by HOLC letters? i.e. are 80% low density homes in A grade zones?

  2. what about census population, census demograhpic + income characteristics?

working progress but very interesting.